Wordstream
Keyword ToolFavorite!
Wordstream provides the most comprehensive and accurate keyword suggestions
and relative volume estimates of any free or paid keyword suggestion tool
or keyword software on the market. It was designed to generate more accurate
keyword suggestions by aggregating over 1 billion unique keywords.

SpyfuFavorite!
Spyfu enables you to spy on your online competitors and download their keywords
and Adwords ads. It also provides ad histories, ad budgets for your competitors
and much more!

Wordtracker
Wordtracker helps website owners and search engine marketers identify
keywords and phrases that are relevant to their or their client's business
and most likely to be used as queries by search engine visitors. Marketers
can also determine how many competing sites are using those keywords and
can identify the phrases that have the greatest traffic potential.

Keyword
Discovery
Keyword Discovery's keyword data is compiled and collected from a number
of search engines to provide a far more accurate cross section of searches
performed world wide. Simply type a seed keyword and have Keyword Discovery
generate the top 100 keywords for you.

Keyword
Spy
KeywordSpy enables you to perform advanced keyword research and keyword
tracking and study what your competitors have been advertising in their
Adwords campaigns and Other PPC campaigns. You can get complete in-depth
analysis, stats, budget, affiliates & ad copies of your competitors.

Webmaster
Toolkit
The Keyword Research Tool will help you research appropriate words and
phrases to include in your webpage's body text to aid in promotion. Simply
enter the sort of word of phrase you wish to be found under, and the tool
will suggest some additional words and phrases you can think about using.

MSN
Keyword Forecast
This tool uses time series forecasts to predict future impressions, while
taking into account seasonality and historical trends. Before launching
your SEO or SEM campaign, use this tool to get forecasts of search volume
and demographic predictions for your selected keywords.

MSN
Keyword Group Detection
This tool helps you find groups of words from the pool of online queries
that are related or similar to keywords that you enter. This keyword research
tool also detects the common misspellings of the keywords entered. This
can help merchants to include commonly misspelled keywords when bidding
for lists of keywords.

MSN
Search Funnels
Customers often perform searches by typing related keywords in specific
sequences. You can use the adCenter search funnel tool to help visualize
and analyze your customers' search behaviors.

CompeteFavorite!
Use Compete Search Analytics to discover keywords proven to drive engagement,
analyze paid and natural search breakouts at the keyword level, view two
years of historical search referral trends, find the data you need with
customized filters, and easily track your performance against competitors
and peers.

QuantcastFavorite!
Quantcast’s free audience measurement for marketers provides detailed
user demographics and deep audience insights at the campaign, site and conversion
level. This information includes traffic, demographics, geography, site
affinity and categories of interest.

iSpionage
ISpionage reveals related keywords for your search terms, the numer of PPC
and SEO competitors the keyword has (and who they are), their ads and keywords
and how they are using Social Media!